1. Field of the Invention
The present invention relates a vehicle brake system, and particularly to a vehicle brake system which is adapted to obtain a parking brake applied state by virtue of the function of hydraulic pressure.
2. Description of the Background Art
A vehicle brake system of this general type is known in, for example, Japanese Unexamined Patent Publication No. JP-A-10-512947 (also referred to herein as Patent Document No. 1).
Incidentally, in Patent Document No. 1, a brake piston is divided into front and rear brake pistons, a spring is provided in a contracted state between a transmission member which is in abutment with a front end of the rear brake piston and a closure plate that is fixed to the front brake piston, a latch, which is adapted to be mesh engagement with internal teeth cut into an internal surface of a brake caliper at the rear of the front brake piston, is accommodated within the brake caliper in such a manner that the latch is brought into engagement with the internal teeth in such a state that the transmission member is in abutment with a front end of the rear brake piston, whereas the engagement of the latch with the internal teeth is released by virtue of a biasing force of the spring when the transmission member moves relatively forwards from the front end of the rear brake piston, and an auxiliary piston, which is adapted to move the transmission member axially relative to the rear brake piston, is fitted slidably in the rear brake piston. However, since the internal teeth have to be cut into the internal surface of the brake caliper and the latch is made to be accommodated in the brake caliper while the brake piston is divided into the front and rear brake pistons, the inside construction of the brake caliper becomes complex.